Thanks to this forum for saving me money and saving me from wasting time at the dealership .I got the T/M failure visit dealer message and my Leaf was freaking out when I tried to start it. While waiting for a tow to the dealership I read this topic. I had a car jump starter I got for Christmas and when I hooked it up to the battery, the car started fine.

So instead of towing to the dealer and the subsequent expense and trip to get the car back, I shopped a new battery, I got another lead acid battery, a local brand called Deka on sale for $82. I had trouble finding a matching battery until I found the Deka. The major chains kept trying to sell me a $237 Optima battery. The Deka only has 18mo warranty, I guess I’ll see how long it lasts and if it can handle the demands placed on it by the Leaf.

Charge the new battery fully with an external charger, and then give it an occasional external charge if the resting voltage is less than 12.6 volts after that. This will extend the battery's life. If the resting voltage stays above 12.5 volts don't worry about it.

2013 "Brilliant Silver" SV with Premium and no QC, a 2009 Vectrix VX-1 W/18 Leaf modules, and 3 EZIP E-bicycles.PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

LeftieBiker wrote:Charge the new battery fully with an external charger, and then give it an occasional external charge if the resting voltage is less than 12.6 volts after that. This will extend the battery's life. If the resting voltage stays above 12.5 volts don't worry about it.

Should I check the charge using a multimeter with car off, or can I use the reading from Leaf Spy?

I came back from a 2 week vacation to find that my 12volt battery had died. Called AAA, who tested the battery, advised me to get a new one, and $147 later my 2012 LEAF was good to go once again. After 6 and a half years, I am still loving driving my LEAF.

powersurge wrote:You cannot estimate your 12v battery by time. It depends on how it is stressed, and how well it keeps at a full charge.

I recently replaced an ORIGINAL EQUIPMENT battery that was 10 years old!!

The battery can be measured objectively, but it takes more than a simple voltage measurement. It must be placed under a substantial and calibrated load. Load testers can be had fairly cheap (around $20 for a 100-amp tester). This will tell you the general condition of the battery instead of just measuring the surface charge. ICE vehicles have a built-in "load test" of a sort, in the form of the starter motor. Sluggish starts generally let ICE drivers know when the end is near. With EVs it will sneak up on you unless you load-test periodically.

The other aspect is sudden failure, which can occur in flooded batteries as grid material is shed over time and accumulates on the bottom of the case. Batteries are designed with room at the bottom for this debris to collect, but if/when it gets deep enough to contact the plates that's the end of the battery. So that is an age-related failure mode that is more difficult to predict.

powersurge wrote:You cannot estimate your 12v battery by time. It depends on how it is stressed, and how well it keeps at a full charge.

I recently replaced an ORIGINAL EQUIPMENT battery that was 10 years old!!

The battery can be measured objectively, but it takes more than a simple voltage measurement. It must be placed under a substantial and calibrated load. Load testers can be had fairly cheap (around $20 for a 100-amp tester). This will tell you the general condition of the battery instead of just measuring the surface charge. ICE vehicles have a built-in "load test" of a sort, in the form of the starter motor. Sluggish starts generally let ICE drivers know when the end is near. With EVs it will sneak up on you unless you load-test periodically.

The other aspect is sudden failure, which can occur in flooded batteries as grid material is shed over time and accumulates on the bottom of the case. Batteries are designed with room at the bottom for this debris to collect, but if/when it gets deep enough to contact the plates that's the end of the battery. So that is an age-related failure mode that is more difficult to predict.

I agree with everything you said..... I said that you cannot estimate a battery's life span by time (years). Yes, I know that the health of the battery is a load test.